What size motor?

[alderman]

I have a older starcraft 14' aluminum fishing boat, manfactured in the mid 1960's. It has no rating plate, don't know if it has came off or just never had one. The gentleman I bought it from says it did have one at one time and it was rated for 40 hp. The boat is 14' long beam is 60" and a vee design. The transom has three support legs. I have a 5hp sea king that came with this rig and it runs fine and will work for the smaller lakes I will fish. I like to run the missouri river sometimes and would like to use a 15-25 Hp. Is there some rule of thumb or a formula for calculating the HP rating on a boat?<br />The boat is in great shape and will work fine, just need more horses for the river and larger lakes.

 

[Chris1956]

Re: What size motor?

alderman, 40HP sounds like a bit much for that boat, especially with tiller steering. We put a 30HP motor on a neighbors 16' aluminum boat. We reinforced the transom with 1.5" lumber to assure it didn't flex. The boat (tiller steering) had too much weight in the rear, and it was scary while accelerating. Therefore experience indicates that the 15HP motor should work fine. <br /><br />There is also a Coast Guard formula for calculating max HP rating. It is on the net, but I do not have the URL for it!

 

[gsbodine]

Re: What size motor?

here ya go, Chris and alderman:<br /><br /> http://www.uscgboating.org/regulations/boatbuilder/part1/reg33_183_4a.htm <br /><br />HTH,<br />ON

 

[alderman]

Re: What size motor?

Thanks for the info and the Coast Guard Link. I would not attempt a 40HP on a 14 footer would be kinda like a runaway team of horses on a john deere #5 mower. Grab a hand full of something and hang on. I'am thinking a 25HP max. I'll check out the Coast Guard site. Thanks Again

 

[woodrat]

Re: What size motor?

Hmmm. I have a 13' Boston whaler here in the yard rated for 40 horsepower and that's what it has had since it came off the lot. The speedo doesn't work, but I'm guessing that she does about 35 knots on flat water. My family water skied with that boat for several summers. My 16' aluminum Valco is rated for 60 hp and has a 60 horse yamaha 2 stroke Pro on it, and she'll do about 29 knots in flat water, and feels pretty safe doing so. <br /><br />And yes, in the whaler with the throttle wide open, you do want to grab something and hang on...

 

[alderman]

Re: What size motor?

I bet that Boston whaler do scoot with a 40. My water ski's have long since gave up the ghost. Not to mention my knees and shoulder just aren't up to it anymore. It's flat water fishing with poles and a ocasional river run with trot lines and limb lines for me. Based on the Coast Guard web site this old boat should handle a 30 with no problem. I'am gonna stick with the 5 for flat water and I think now a 20 for the mighty Mo.<br />Thanks again for all the help guys. I allways get the info I need from all the good folks hear.